Picture this: Your wacky uncle appears with an ancient scrap of paper. Together, you decode its inscription, and you learn that an Icelandic volcano opens a shortcut into the Earth’s mantle. He insists that you travel to Reykjavik, hire a brutish guide named Hans, and crawl in this fiery crevice, armed only with hemp ropes and canteens of water.

Some of us might love this idea, but Axel Lidenbrock does not. In Bernardo Mena’s faithful adaptation of the Jules Verne novel, Teatro Espressivo tells the story of blustery Otto Lidenbrock, his nervous nephew Axel, and their odyssey underground. Emilio Aguilar has directed a highly inventive stage version of “Journey to the Center of the Earth,” turning a pulpy 1864 adventure story into good-humored family theater.

Indeed, this Spanish-language version of “Journey” is fun, creative, and fast-paced. The script is easy to follow, even for unsteady Hispanophones, and because it’s aimed at mature children, the show is just right length – about one uninterrupted hour.

When the story requires sea monsters and echoing caverns full of stalactites, Teatro Espressivo finds ways to replicate these scenes on stage. The production relies heavily on Antonio Calvo’s multimedia magic, including projected images and video. Rodrigo Oviedo’s sound design is top-notch, interweaving special sound effects with cinematic music.

In less capable hands, the project could have been a disaster. “Journey to the Center of the Earth” is one of Verne’s lesser works – compared to “20,000 Leagues Under the Sea” and “Around the World in Eighty Days,” the novel is astoundingly mediocre. Captain Nemo and Phileas Fogg are among the most beloved characters in Victorian literature, while Axel Lidenbrock is a spineless nobody. Even the Nautilus (a submarine) has more personality than Axel and Otto. Every adaptation of “Journey” has been laughably awful, and part of its B-movie silliness is the premise: In reality, the “center of the earth” is a hyper-dense sphere of liquid rock. Nobody could tunnel past the earth’s crust, much less dig through thousands of miles of magma to discover subterranean oceans and light-emanating gas.

Yet while this novel makes for terrible movies, its story is perfect for an 8-year-old who is all but certain to love dinosaurs, caves and crazy uncles in top hats. Verne’s other tales are too dark (“20,000 Leagues”) or too slow (“Eighty Days”) to keep a preteen’s attention, but “Journey” is perfect: Children will one day ask, “Mom, what’s inside the earth?” Now parents have an answer: “Brontosaurus.”

To keep the play engaging, director Emilio Aguilar requires some special effects. (You can’t just pantomime a wooden raft getting vomited out a volcanic tunnel and into the Italian countryside). But Aguilar uses these spectacles tastefully: When Otto, Axel, and Hans march across an Icelandic glacier, it is their posture and labored speech that make the scene come alive, not just the projected background of jagged peaks. Indeed, the actors perform with energy and precision. As Axel, Manuel Martin is entertainingly neurotic, and he transforms nicely from slacker to hero. Rubén Darío Arena plays Uncle Otto as a gruff and blustery bachelor, and because he has a black mustache and pushy demeanor, you expect him to turn mad or villainous at any moment.

The scene-stealer is Alice García, who plays Alex’s plucky love interest, Gräuben. Granted, Gräuben doesn’t join the men on their adventure, so her character has little to do except convince Axel that he has more courage than he realizes. When Axel makes up excuses for why he should stay home, Gräuben insists, “You have to go!” It’s clear, from García’s incredible physicality, that the actress is underused and deserves a much bigger part. If Espressivo ever adapts “Eighty Days,” maybe she’ll get to play Aouda. Given the quality of this “Journey,” such a sequel would probably be spectacular.